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Vol. XIX Washington, D. C, June 15, 1920 No. 6 



EFFECT OF MANURE-SULPHUR COMPOSTS UPON THE 

 AVAILABILITY OF THE POTASSIUM OF GREENSAND 



By A. G. McCall, In Charge of Soil Investigations, and A. M. Smith, Chemist, Soil 

 Investigations, Maryland Agricultural Experiment Station 



/ INTRODUCTION 



The greensands and the greensand marl deposits of the eastern United 

 States have long been regarded as a possible source of potassium for 

 agricultural purposes. The literature of the last half of the nine- 

 teenth century contains many reports of the success that has followed 

 the application of greensand marls to soils in Maryland, New Jersey, 

 and other eastern States. Since many of these marls contain a high 

 percentage of calcium carbonate, it is probable that the good results 

 that followed their use was due in many cases to their lime content rather 

 than to the potassium which they contained. 



During the continuance of the war with Germany, the scarcity and 

 the consequent high price of readily soluble potassium salts has served 

 to direct attention in this country to the possibility of utilizing for 

 agricultural purposes the potassium of these greensand deposits and has 

 indicated the desirability of devising some efficient method of treatment 

 that would render the potassium more available. At the suggestion of 

 the fertilizer committee of the National Research Council, the Department 

 of Soil Investigations of this Station has studied the effect of composting 

 greensand with sulphur, manure, and other materials with a view to 

 making available the potassium contained in the greensand. It is the 

 purpose of this paper to report the results of this investigation. 



HiSTORICAIv 



As early as 1830 Thomas Gordon called attention to the great benefits 

 that farmers in New Jersey were deriving from the use of marl. In a 

 geological report published in 1868, Cook {6y gives the analyses of a 

 number of samples of marl from New Jersey and states that the use of 

 this material has raised the land from a low state of exhaustion to a high 

 stage of agricultural development. He states that some of these marls 

 are so acid that heavy applications of as much as 50 tons to the acre 

 cr> 



CVI ' Reference is made by ntrmber (italic) to " Literature cited, " p. 255-256. 



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Journal of Agricultural Research, Vol. XIX, No. 6 



Washington, D. C. June 15, 1920 



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